French patent application No. 93 04272, filed on 9 Apr. 1993 by the present Applicants, describes an apparatus of the above type which comprises elements arranged in succession in a substantially horizontal direction along the longitudinal axis of the vehicle. An apparatus of this type has a particularly compact structure, which enables it to be easily incorporated in the central part of the fascia of the motor vehicle It is most particularly Suitable for vehicles of the kind known as "monocorps" vehicles, in which the driving station and the fascia extend in the longitudinal direction of the vehicle.
In the above mentioned French patent application, the apparatus described therein provides a heating apparatus and a ventilating apparatus each of which has its own separate blower, these two apparatuses being arranged one behind the other.